Hey all! This is my first time posting on this forum, so I would like to introduce myself a bit. We are a little hobby farm in Western Washington. We used to raise show and milk goats, but we have since just reduced our stock to chickens. (I don't mind all that much!) We have been experimenting with Old English, Araucanas and other bantams to see which breed we like best and what's good for free-range on our current property. We also bought some stock from Greenfire, to use to breed and sell. The chicken in question in a 5 month old Cream Legbar hen from Greenfire who has recently developed a welt, hard thing on the joint of the top of her leg. She had a slight limp the day before, but I dismissed it as her falling on it funny, looking back I should've checked it out. It got worse today. We treated her for mites a few days ago as she was exhibiting signs of infestation, and replaced the roosts. I'm not sure what it could be, I'm not very well read in all the chicken ailments. None of the other chickens have been showing symptoms.